Optical device, particularly a polarimeter, for detecting inhomogeneities in a sample

Abstract

An optical device, particularly a polarimeter, is provided for analyzing a liquid sample, having: a light-generating system for generating light for the surface irradiation of the sample; a detection system which is set up for the spatially resolved detection of light which originates from the transmission of the light provided for the surface irradiation through the sample; a telecentric optical system with a lens between the sample and the detection system and with an aperture diaphragm in the focal plane of the lens between the lens and the detection system.

The invention claimed is: 
     
       1. An optical device for analyzing a liquid sample, comprising:
 a light-generating system for generating light for surface irradiation of the sample through an inlet window of a cuvette, wherein the inlet window traverses a longitudinal axis of the cuvette; 
 a detection system arranged to intercept the surface irradiation after passage through the sample; 
 a telecentric optical system with a lens arranged between the sample and the detection system and with an aperture diaphragm in a focal plane of the lens between the lens and the detection system. 
 
     
     
       2. The device according to  claim 1 , wherein the telecentric optical system has a further lens arranged between the aperture diaphragm and at least one part of the detection system. 
     
     
       3. The device according to  claim 1 , further comprising an actuator that positions at least one of a homogenizer, a reflector, and a polarization state analyzer into an optical axis or an analysis beam path. 
     
     
       4. The device according to  claim 1 , further comprising a temperature sensor for measuring a temperature of the sample. 
     
     
       5. The device according to  claim 1 , further comprising a processing and control system which receives signals from the detection system, based on which the processing and control system determines a two-dimensional image of the irradiated sample, which represents an optical projection of the sample along an optical axis, wherein the processing and control system is configured to display and/or store and/or analyze the two-dimensional image by use of image processing, to detect an inhomogeneity within the sample. 
     
     
       6. The device according to  claim 1 , further comprising a polarization state analyzer for changing a polarization state of light which has passed through the sample, wherein the polarization state analyzer is arranged in an analysis beam path upstream of at least a part of the detection system. 
     
     
       7. The device according to  claim 1 , wherein the light-generating system is further configured for generating a measuring light beam, which propagates through the sample along an optical axis. 
     
     
       8. The device according to  claim 5 , wherein the processing and control system is constructed to control a polarization state generator and/or a polarization state analyzer, so that an orientation of a polarization direction of light, which is let through by the polarization state generator and/or the polarization state analyzer, is set to minimize an intensity detected by the detection system,
 wherein the processing and control system is configured to determine from the set orientation a rotation value of a rotation of a polarization direction of the light based on irradiation of the sample with a measuring radiation and/or a concentration of an optically active component in the sample. 
 
     
     
       9. The device according to  claim 6 , wherein the detection system comprises a surface detector in the analysis beam path. 
     
     
       10. The device according to  claim 9 , wherein the surface detector is configured for detecting the measuring light beam transmitted through the sample when the polarization state analyzer is pivoted into the analysis beam path. 
     
     
       11. The device according to  claim 9 ,
 wherein the analysis beam path comprises a first analysis beam path and a second analysis beam path which is different from the first analysis beam path, 
 wherein the detection system comprises, in the first analysis beam path, the surface detector for detecting light which originates from transmission through the sample and, in the second analysis beam path, a photodetector arranged downstream of the polarization state analyzer for detecting the measuring light beam transmitted through the sample. 
 
     
     
       12. The device according to  claim 11 , further comprising a beam splitter which is arranged between the sample and the detection system and is set up to simultaneously direct a portion of the light transmitted through the sample along the first analysis beam path onto the surface detector and another portion of the light transmitted through the sample along the second analysis beam path onto the photodetector. 
     
     
       13. The device according to  claim 11 , further comprising a reflector which is arranged between the sample and the detection system such that it can be pivoted in and pivoted out, in order to alternatively direct light transmitted through the sample along the first analysis beam path either onto the surface detector or along the second analysis beam path onto the photodetector. 
     
     
       14. The device according to  claim 7 , further comprising a polarization state generator which is arranged upstream of the sample in the optical axis and is configured to generate the measuring light beam with a defined polarization state together with the light generating system. 
     
     
       15. The device according to  claim 7 , further comprising a homogenizer which is arrangeable in the optical axis. 
     
     
       16. The device according to  claim 7 , wherein the light-generating system comprises a first light source for generating the surface irradiation and a second light source for generating the measuring light beam, wherein the device further comprises an illumination mirror that directs one of homogeneous light and/or the measuring light beam through the sample. 
     
     
       17. The device according to  claim 15 , wherein the homogenizer is pivotable out of the optical axis and into the optical axis, to alternatively direct one of a measuring light beam or a homogenized surface irradiation through the sample. 
     
     
       18. The device according to  claim 16 , wherein the illumination mirror is partially transparent to simultaneously direct both the homogeneous light and the measuring light beam through the sample, wherein the homogeneous light provided for surface irradiation does not comprise any wavelength which is contained in the measuring light beam, and wherein the detection system further comprises a wavelength-selective component. 
     
     
       19. The device according to  claim 16 , wherein the illumination mirror is movable to various positions to alternatively direct one of the homogeneous light or the measuring light beam through the sample, wherein the homogeneous light provided for surface irradiation comprises a wavelength which is equal to a wavelength of the measuring light beam.